Exceptions all reported as "Unknown exception"

[claremacrae]

Describe the bug

Catch2 does not report the text of unexpected exceptions (ex.what()) on the console.

Expected behavior

If exceptions are enabled, and code in a TEST_CASE throws an exception derived from std::exception, the exception.what() text should be displayed to the user.

Actual behavior
The following is displayed:

Failure:
unexpected exception
Process finished with exit code 1

Reproduction steps

main.cpp

#define CATCH_CONFIG_MAIN
#include "catch2/catch.v2.11.0.hpp"

Catch2Tests.cpp

#include "catch2/catch.v2.11.0.hpp"

#include <exception>

TEST_CASE("TestStreamableObject")
{
    throw std::runtime_error("I should be printed");
}

CMakeLists.txt

project(catch2_only)
set(CMAKE_CXX_STANDARD 11)
add_executable(${PROJECT_NAME}
        main.cpp
        Catch2Tests.cpp
        )
target_link_libraries(${PROJECT_NAME} Catch2::Catch2)

add_test(NAME ${PROJECT_NAME} COMMAND ${PROJECT_NAME})

Platform information:

• OS: macOS Catalina 10.15.4
• Compiler+version: Xcode C++ compiler, g++9, clang-9
• Catch version: v2.11.0

Additional context

• I believe this has been reported before, in Exceptions all reported as "Unknown exception" #463
• This has been seen by multiple users of ApprovalTests.cpp, on multiple different machines
• It's reproducible with the Xcode C++ compiler, g++9, clang-9
• I'm building in CLion, but I don't see why that would matter
• I cannot seen anywhere in the Catch2 source code that prints out just unexpected exception - so I am stumped as to where this comes from
• I've gone back through multiple old catch releases, back to v2.0.1 - and have not been able to get the exception text to print
• But I swear that I previously was able to get exception text displayed
• I paired with someone else who saw this on their Mac, with a similarly minimal example - and they switched to Windows and the same code did display the exception text
• So I suspect it may be a Mac-specific issue (but compiler-independent - I've been working on Mac for less than a year)

[claremacrae]

Eventually it dawned on me to run the Catch2 program in the console, and it ran fine and showed the exception text.

So I asked Phil Nash about it, and he pointed me to the 2-year old CLion issue about this:
https://youtrack.jetbrains.com/issue/CPP-11919

So I'm closing this, as it's not a Catch2 issue...

[claremacrae]

For info, the underlying CLion issue mentioned above has been fixed in CLion release 2020.2 (available via Early Access Program as of early July 2020)